There is a desperate attempt being made to strike a balance between the environmental ecology with that of the biome within. With the evidence that probiotics may be efficient in restoring the ecology of the skin thereby lowering the incidence and severity of cutaneous disorders has been greeted with a mixture of excitement and skepticism.
What are probiotics?
Probiotics can be defined as live microbial food supplements that are beneficial to the host health when administered in adequate quantities. Emerging research is finding that the benefits of probiotics may be extending beyond the digestive system. Evolving theory suggests that the organisms used as a probiotic may help in forming an effective protective barrier thereby resisting the pathogenic microbes from taking over.
The Science behind probiotics effect on skin:
Most bacterial cells that live inside or on the body are harmless and studies have shown that infact they may be protective and extremely beneficial to the body’s normal functioning. Researches are on to investigate how oral administration or topical application of these bacteria may be beneficial in cutaneous conditions. These researches are based on the gut-brain-skin axis theory which was introduced almost about 80 years back.
Topical probiotics act by the mechanism of bacterial interference where they protect the skin and interfere with the ability of a pathogenic bacteria to evoke an immune response.
Indications in dermatology:
1. Atopic dermatitis
2. Eczema
3. Acne vulgaris
4. Acne rosacea
5. Photosensitive dermatoses
6. Skin and soft tissue infections
7. Anti-ageing
It has been noted that probiotic initiation during the third trimester of pregnancy in atopic mothers has been efficient in delaying the onset and reducing the severity of the disease in the child (1). So the question is why are we not treating all atopic mothers with probiotic supplementation? Initial studies of different strains of oral lactobacillus for both prevention and treatment of atopic dermatitis were encouraging, but follow-up reviews and meta-analyses have been conflicting (2-6). However having said that newer researches show that topical and oral probiotic administration has helped to increase ceramide levels in the skin barrier thereby reducing the severity of atopic dermatitis and ensuring longer remissions (7).
In these patients the living bacteria on the skin surface is identified as foreign and the body launches an immune response against them thereby causing inflammation. The probiotics act by bacterial interference thereby suppressing this immune sensitization. It has also been postulated that the bacteria in probiotics have a capacity to produce chemical substance which may be lethal to the pathogenic bacteria thereby reducing their load on the skin. This is probably one of the rationale behind using them in combination with antibiotics in cases of skin and soft tissue infections. Stress alone or along with increased intake of processed food can slow digestion and motility of the gasto intestinal tract thereby leading to proliferation of unhealthy bacteria .people who are predisposed to acne or rosacea can experience flares as a result of this shift in microbiome and subsequent inflammation. Parodi and colleagues showed in 2008 that patients with rosacea had a ten-fold greater incidence of small intestinal bacterial overgrowth as compared to healthy controls (8). Further studies examining the therapeutic benefit of oral and topical probiotic administration in mild acne patients within the last decade have been promising, with proposed theories including decreased release of inflammatory mediators as well as increased production of ceramide and skin barrier restoration(9,10). We in cohesion with the studies opine that although probiotics may not stand as a monotherapy for acne and rosacea it can be definitely considered as a safe and effective adjuvant therapy for the same with some effect on maintenance and long term remission in these patients.
The usage of probiotics in combination with antibiotics also seem beneficial due to modification of the gut microbiome thereby combating the adverse effects like diarrhea associated with consumption of few antibiotics. Wong and colleagues suggested that probiotics may help to normalize disruptions in human microbial communities and bacteria-host interactions that contribute to non-healing wounds (11).
Photoprotection and antiageing properties of probiotics, although the mechanism of action still remains elusive may be attributed to the reduction of inflammatory response and immune modulation. It is hypothesised that bifidobacterium attenuated the damage to the tight junction structure and basement membrane induced by chronic UVB irradiation, possibly via measurably-decreased interleukin-1-beta production in the skin.
The controversies:
The sceptics in usage of probiotics have been fuelled by disappointing results with probiotics in the treatment of eczema as evidenced by the Cochrane Database system in 2008. Selection of the right probiotic for adequate effectiveness is crucial. It has been found that the usage of same probiotic agent in two different population groups have given variable results.
Future perspectives:
Probiotics is an open arena with multiple possibilities. It has stimulated world wideinterest to carry out multi centric well designed larger population based studies so as to validate its use in dermatology and expand the therapeutic horizons.
Conclusion:
Any new venture when undertaken must not be met with prejudice or scepticism. A wider and open eye view of probiotics would help us in providing a more promising and safe, therapeutic and preventive modality in times to come for the chronic cutaneous disorders. While it is tempting and adventurous to embark on the broad utility spectrum of probiotics, such enthusiasm must be tempered with careful study and consideration.
References:
1. Lee J, Seto D, Bielory L: Meta-analysis of clinical trials of probiotics for prevention and treatment of pediatric atopic dermatitis. J Allergy ClinImmunol 121:116-121.e111, 2008
2. Kalliomäki M, Salminen S, Arvilommi H, Kero P, Koskinen P, Isolauri E. Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial. Lancet. 2001; 357(9262):1076-9.
3. Weston S, Halbert A, Richmond P, Prescott SL. Effects of probiotics on atopic dermatitis: a randomised controlled trial. Arch Dis Child. 2005;90(9):892-7.
4. Van der aa LB, Heymans HS, Van aalderen WM, Sprikkelman AB. Probiotics and prebiotics in atopic dermatitis: review of the theoretical background and clinical evidence. Pediatr Allergy Immunol. 2010;21(2 Pt 2):e355-67.
5. Pelucchi C, Chatenoud L, Turati F, et al. Probiotics supplementation during pregnancy or infancy for the prevention of atopic dermatitis: a meta-analysis. Epidemiology. 2012; 23(3):402-14.
6. Boyle RJ, Bath-hextall FJ, Leonardi-bee J, Murrell DF, Tang ML. Probiotics for treating eczema. Cochrane Database Syst Rev. 2008;(4):CD006135.
7. Di marzio L, Cinque B, Cupelli F, De simone C, Cifone MG, Giuliani M. Increase of skin-ceramide levels in aged subjects following a short-term topical application of bacterial sphingomyelinase from Streptococcus thermophilus. Int J Immunopathol Pharmacol. 2008; 21(1):137-43.
8. Parodi A, Paolino S, Greco A, et al. Small intestinal bacterial overgrowth in rosacea: clinical effectiveness of its eradication. Clin Gastroenterol Hepatol. 2008;6(7):759-64.
9. Muizzuddin N, Maher W, Sullivan M, Schnittger S, Mammone T. Physiological effect of a probiotic on skin. J Cosmet Sci. 2012; 63(6):385-95.
10. 4. Di marzio L, Cinque B, De simone C, Cifone MG. Effect of the lactic acid bacterium Streptococcus thermophilus on ceramide levels in human keratinocytes in vitro and stratum corneum in vivo. J Invest Dermatol. 1999;113(1):98-106.
11. Wong VW, Martindale RG, Longaker MT, Gurtner GC. From germ theory to germ therapy: skin microbiota, chronic wounds, and probiotics. Plast Reconstr Surg. 2013; 132(5):854e-861e.
